feat: task notification window

[jonathanbataire]

Description

Adds ability to have configurable task notification window when notifications can be fired.
defaults to a 08:00 to 19:00 window

Fixes medic/cht-android#433

Code review checklist

• UI/UX backwards compatible: Test it works for the new design (enabled by default). And test it works in the old design, enable can_view_old_navigation permission to see the old design. Test it has appropriate design for RTL languages.
• Readable: Concise, well named, follows the style guide
• Documented: Configuration and user documentation on cht-docs
• Tested: Unit and/or e2e where appropriate
• Internationalised: All user facing text
• Backwards compatible: Works with existing data and configuration or includes a migration. Any breaking changes documented in the release notes.
• AI disclosure: Please disclose use of AI per the guidelines.

License

The software is provided under AGPL-3.0. Contributions to this project are accepted under the same license.

[github-actions]

This PR is now marked "stale" after 30 days without activity. It will be closed automatically in 10 days unless you add a comment, push new changes or remove the "stale" label.

[mensch72]

AI disclosure: This review was prepared by GitHub Copilot, an AI coding agent, through this account with the account holder’s explicit authorization.

This changes existing behavior when no notification window is configured. getNotificationSettings() always supplies 08:00–19:00, whereas Android treats missing start/end as unrestricted. Deployments would therefore acquire a work-hours assumption without opting in.

Could the window remain absent unless tasks.task_notification_window is configured? A regression test should verify that an unconfigured deployment preserves unrestricted notifications.